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-   -   R12 Vacuum (https://67-72chevytrucks.com/vboard/showthread.php?t=825552)

44SAA 09-05-2021 08:28 PM

R12 Vacuum
 
1 Attachment(s)
Started to pull vacuum on my OEM R12 system and noticed the valve on the high side is a smaller diameter than the low side valve. As a result my R12 dual gage canít fit on the high side valve. Can I just pull vacuum using the low side only? Thank you

Ziegelsteinfaust 09-05-2021 08:37 PM

Re: R12 Vacuum
 
Yes it is just not as fast.

Katrina/10 09-06-2021 08:23 AM

Re: R12 Vacuum
 
You'll need a high-side adapter to use both gauges. They are still available.

44SAA 09-06-2021 12:27 PM

Re: R12 Vacuum
 
2 Attachment(s)
While the threads on my yellow jacket R12 gauge fit on the low side- the schraeder valve on the low side isnít being depressed by the valve on gauge set. Katrina- is this the adapter you are speaking of. Kinda frustrated as I bough the yellow jacket gauge set labeled R12 as I figured it would hook right up? Thank you

Katrina/10 09-06-2021 01:04 PM

Re: R12 Vacuum
 
The high side adapter looks like this: https://www.ebay.com/itm/153812368295

You attach it to the evaporator inlet then screw on your yellow jacket hose.

If you get no pressure reading on the gauge, there is something wrong with the valve or hose. Or, no refrigerant.

Just call me Sean 09-06-2021 02:32 PM

Re: R12 Vacuum
 
The blue line hooks there. Looks like you have the yellow in your hand.

Corts60 09-06-2021 06:03 PM

Re: R12 Vacuum
 
Quote:

Originally Posted by Just call me Sean (Post 8967147)
The blue line hooks there. Looks like you have the yellow in your hand.

Yep. Yellow one goes to the vacuum pump. Are you using a micron gauge to tell how far down you are pulling the system?

44SAA 09-06-2021 06:15 PM

Re: R12 Vacuum
 
Thank you. I realize the yellow hooks up to the vacuum pump and the blue to low side. I just posted that pic to show the fitting that will not engage the schraeder valve as it is identical to the blue hose fitting. Thank y’all for the help. It’s been frustrating.

44SAA 09-06-2021 06:26 PM

Re: R12 Vacuum
 
Quote:

Originally Posted by Corts60 (Post 8967232)
Yep. Yellow one goes to the vacuum pump. Are you using a micron gauge to tell how far down you are pulling the system?

Hey Corts- not sure what a micron gauge is. I posted a picture of the gauge I am attempting to use. Thanks


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